The following report has been submitted to the On-call interface.
On-call events -> Injection System
Title: Fast unlock crysis
Author(s): spinicelli, chiummo
|Called at: 18:30, 14-05-2021, by: Menzione|
|Remote intervention: Started: 18:30, 14-05-2021; Ended:|
|On-site intervention: Started: ; Ended:|
|Operator when issue resolved: Menzione|
In the late afternoon IMC and RFC started to suddenly and repetitively unlock, creating problems to the planned activities of the ISC team.
After a first analysis, it is clear that this problem is different from the one reported during the night of between 12th and 13th May ( 51771 ). Indeed, that phenomenon was a slow decrease of the power due to mode competition caused by a mode-hope instability, that has been solved today.
Instead, analyzing the raw data of some of this evening unlocks (plot 1, 2, 3) we can observe typical behaviour of EOM corrections saturation that triggers the unlock of IMC and RFC. After a quite long period of instability between ~17:30 and 19:30 UTC, those unlocks started to calm down a little.
Up to now, it's unclear what could trigger these crysis. We leave the system with all loops closed.
* Note that any files attached to this report are available in the On-call interface.